Product Documentation

Use Cases: Web insight

May 04, 2017

Web Insight enables visibility into enterprise web applications and allows IT administrators to monitor all web applications being served by the NetScaler ADC by providing integrated and real-time monitoring of applications. Web Insight provides critical information such as user and server response time, enabling IT organizations to monitor and improve application performance.

Monitoring Cache Server Performance

Updated: 2014-06-18

A NetScaler deployment can optimize cache server utilization to reduce bandwidth consumption and speed up data retrieval. The NetScaler ADC analyzes incoming requests, sends cacheable requests to cache servers, and sends non-cacheable requests or dynamic HTTP requests to origin servers. NetScaler Insight Center analyzes the traffic flowing through NetScaler ADC to cache servers and origin servers, and provides useful information about the cache performance, such as:
  • Bandwidth saved while serving requests from the cache server instead of the origin server.
  • Bandwidth consumed when requests bypassed the cache server and were served from the origin server.
  • Number of times a URL was accessed from the cache server instead of the origin server.
To analyze the performance of the cache server, you can view the following metrics:
  • Cache Hits: Number of requests served by the cache server.
  • Cache misses: Number of requests served by the origin server because they could not be served by the cache server.
  • Cache bypass: Number of requests served by the origin server because the cache server was bypassed.
  • Cache hits bandwidth consumed: Bandwidth consumed by serving requests from the cache server.
  • Cache miss bandwidth consumed: Bandwidth consumed by serving requests from the origin server when they could not be served from the cache server.
  • Cache bypass bandwidth consumed: Bandwidth consumed by serving requests from the origin server when the cache server was bypassed.

If cache servers are deployed in a network, and cache redirection is enabled on the NetScaler ADC, and appflow logging is enabled for cache redirection, NetScaler Insight Center gathers details such as bandwidth saved and cache servers utilized across a cache farm.

  1. Amount of bandwidth saved in a NetScaler deployment
    The main reason to deploy cache servers is to decrease the bandwidth consumed in retrieving data from the origin servers. A cache redirection report on bandwidth consumed by cache hits versus cache bypasses and cache misses over a period of time can provide a picture of bandwidth saved. The report includes the following details:
    • Bandwidth consumed by origin server versus cache farm
    • Bandwidth consumed by origin server
    • Bandwidth consumed by cache farm
    • Percentage of bandwidth saved by NetScaler ADC
  2. Cache Servers utilized in a cache farm

    You can also view the cache redirection statistics to administer the cache servers. Cache redirection reports provides statistics about cache server utilization in a cache farm.

    For example, you can view the request distribution across cache servers in a cache farm when clients access different domains. The report also shows the bandwidth served by the cache farm, which in turn shows the percentage bandwidth saved by serving content from the cache farm.

    You can view the following details
    • Number of requests distributed across multiple cache servers
    • Responses served locally by the cache farm or cache hit of a cache server
    • Average server processing time for requests served from the cache farm
    • Bandwidth served locally by cache farm
    • Cache misses across the cache farm
  3. Top domains and URLs requested

    Cache redirection reports provide a complete picture of how domains or URLs are being accessed. These reports include the following information about cache performance:

    • Domains or URLs accessed, and the number of requests for each domain or URL
    • Top domains or URLs accessed during specific time intervals
    • Top domains or URLs as determined by number of clients
    • Distribution of domains or URLs with respect to number of requests versus the bandwidth consumed
    • Top Domains by number of requests served from cache farm and origin farm
  4. Usage of Top Clients

    Cache redirection reports give administrators the ability to view cache server usage by clients across different domains and URLs. The reports include the following details:

    • Top clients by total number of requests received
    • Top clients by bandwidth consumed
    • URLs accessed by top clients
    • Domains accessed by top clients
    • Top clients with respect to requests served from cache server versus the origin server

Example

A cache redirection report displays the bandwidth consumed for each specific URL accessed by a client. To view the report:
  1. On the Dashboard tab, expand Web Insight, click URLs, and then select the desired URL

    On the left side of the graph, the dashboard displays the data for cache-hits bandwidth consumed, cache-miss bandwidth consumed, and cache-bypass bandwidth consumed.

Identifying the root cause of slow performance issues

Updated: 2014-06-18

Scenario 1

Consider a scenario where two clients are accessing the same SharePoint server, but one client is experiencing slow performance.

The client might be experiencing slow performance while accessing the SharePoint server due to latency on the client network or latency on the server network.

To identify the root cause of the issue, analyze the following metrics:
  • Client Network Latency
  • Server processing time
  • Server Network Latency
To view the client metrics
  1. On the Dashboard tab, expand Web Insight and click Applications.
  2. In the list of applications select Share Point.
  3. Scroll to the Clients graph.
  4. Select the Client Network latency from the drop-down list.

    Note the Client Network Latency values for the clients.

  5. In the Servers graph, select Server Processing Time and Servernetwork Latency and note its value.

Summary

In this example, the Client Network Latency for client 1 (192.168.1.102) and client 2 (192.168.1.100) is 1 second and 103 milliseconds respectively. The server processing time and the server network is latency is low.

This implies that the client is experiencing the slow performance due to latency on the client network and not due to server latency or server processing time.

Scenario 2

Consider another scenario where a client is experiencing slow performance while accessing a URL (Main.html).

The client might be experiencing slow performance while accessing the URL due to high Client Render Time, Client Network Latency, or high application Response Time.

To identify the root cause of the issue, analyze the following metrics:
  • Client Render
  • Client Network Latency
To view the client metrics
  1. On the Dashboard tab, expand Web Insight and click URLs.
  2. In the URLs dashboard select Render Time from the drop down.
  3. Select the /Main.html URL and scroll down to the Clients graph and check the render time for client 192.168.1.105.
  4. In the Clients graph, select Client Network Latency and check the Client network latency value.

Summary

In this example, the Render time is 1 second and the Client Network Latency is 105 milliseconds.

This implies that the slow performance experienced by the is due to the high render time of the client.

The Page Analysis pane shows the embedded objects that are contributing to the high render time.

Scenario 3

Client experiences slow performance while accessing Outlook Web Access (OWA).

The client might be experiencing slow performance while accessing OWA due to latency on the client network or latency on the server network.

To identify the root cause of the issue, analyze the following metrics:
  • Client Network Latency
  • Server processing time
  • Server Network Latency
To view the client and server metrics
  1. On the Dashboard tab, expand Web Insight, click Applications, and then click OWA application.
  2. Scroll down to Servers graph, select Server Processing Time.
  3. In the Clients graph, select Client Network Latency and select Server Network latency in the Servers graph.
  4. Verify if the Server Processing Time is consistently higher than Client Network Latency and Server Network Latency.

Summary

In this example, the Server processing Time is 1.25 seconds, the Client Network latencyis 125 milliseconds and Server Processing Time is 40 milliseconds.

This implies that user is experiencing slow performance while accessing OWA due to the high server processing time.

Display the usage of web applications across different geographical locations on a map

Updated: 2015-04-27

Geo maps functionality in NetScaler Insight Center displays the usage of web applications across different geographical locations on a map. Administrators can use this information to understand the trends in application usage and for capacity planning.

Geo map provides information about the following metrics specific to a country, state, and city:
  • Total Hits: Total number of times an application is accessed.
  • Bandwidth: Total bandwidth consumed while serving client requests
  • Response Time: Average time taken to send responses to client requests.
Geo maps provide information which can be used to address several use cases such as the following::
  • Which region has the maximum number of clients accessing an application?
  • Which region has the highest response time?
  • Which region is consuming the most bandwidth?

The following image provides a snapshot of the geo map:

To view the web application traffic on the geo map, you must first download the geo database file, upload it in NetScaler Insight Center, and then enable geo data collection.

Note:
  • In the above image, asterisk (*) indicates client IP addresses that were not resolved by the geo database file.
  • NetScaler Insight Center does not display geo maps for 5-minute and weekly interval.

To view web application traffic on the geo map, you must download the geo database file, upload it to NetScaler Insight Center, and then enable geo database collection.

To download the geo database file

Download the geo database file from the location http://geolite.maxmind.com/download/geoip/database/GeoLiteCity.dat.gz and extract the GeoLiteCity.dat file from GeoLiteCity.dat.gz.

Note: Currently, Maxmind Geo IP city binary file is the only supported database format.

To upload the geo database file

  1. On the Configuration tab, expand NetScaler Insight Center, and the click Geo Database Files.
  2. From the Action drop-down menu, select Upload.
  3. In the Upload Geo Database File window, click Browse.
  4. Navigate to the location of the geo database GeoLiteCity.dat file, and then click Upload.

To enable Geo data collection

  1. On the Configuration tab, click Inventory.
  2. From the inventory list, select the IP address of the NetScaler appliance for which you want to enable geo data collection.
  3. In the NetScaler Insight Center Inventory Setup pane, select the Enable geo data collection check box.

After you enable geo data collection, the map is available in Web Insight reports for a single application or all applications, or all clients .